Shrinking tube or bending a cone
EDIT

To create a bent conical object. Start with a Curve and a Bezier Circle (Add Curve->Circle) as Bevel object:



Then change the Radius for the control points of the curve:



Other Ideas:

Do the whole object as a curve:



then fill it as a 2D



Then add a bevel:



If you add a Curve->Circle as a bevel Object you can so something like this: